Effect of remifentanil pretreatment on lipid peroxidation following acute myocardial ischemia/reperfusion in rabbits

Objective To investigate the effect of remifentanil pretreatment on lipid peroxidation following acute myocardial ischemia/reperfusion （1/R） in rabbits. Methods Forty healthy adult rabbits of both sexes weighing 1.5-2.5 kg were randomly divided into 5 groups （n = 8 each）： group control （group Ⅰ ）; group I/R（group Ⅱ ）; group morphine pretreatment ＋ I/R （group Ⅲ ）; group remifentanil （group Ⅳ ） and group remifentanil pretreatment ＋ I/R （group Ⅴ ）. The animals were anesthetized with intraperitoneal 2% pentobarbital 45 mg/kg and were mechanically ventilated after tracheal intubation. PET CO2 was maintained between 35-45 mm Hg. Myocardial I/R was induced by iv pituitrin 2.5 U/kg in group Ⅱ , Ⅲ and Ⅴ. In group Ⅰ and Ⅳ normal saline 0.3 ml/kg was injected iv instead of pituitrin. In group Ⅲ morphine 3.3 mg/kg was injected iv at 30 min before iv pituitrin. In group Ⅳ and V remifentanil was infused at 3.3 μg· kg-1 ·min-1 for 30 min before iv normal saline and pituitrin.Venous blood samples were taken before （baseline） and at 24 h and 48 h after iv pituitrin for determination of serum cTnI concentration. The myocardial specimens were taken at T3 after blood sampling for microscopic examination and determination of SOD activity and MDA content. Results Intravenous pituitrin 2.5 U/kg significantly increased serum cTnI concentration and myocardial MDA content and decreased myocardial SOD activity in group Ⅱas compared with group Ⅰ . Morphine or remifentanil preatment significantly attenuated the myocardial I/R-induced changes mentioned above. Microscopic examination showed that myocardial tissue damages were ameliorated in group V as compared with group Ⅱ . Conclusion Remifentanil pretreament can attenuate acute myocardial ischemic injury by inhibiting lipid peroxidation. Key words: Piperidines;  Lipid peroxidation;  Myocardial reperfusion injury